Liquefied gas storage and dispensing system



.June 21, 1938. L. J. WHITE 2 ,121,674

LIQUEFIED GAS STORAGE AND DI$PENSING.3YSTEM 7 Filed May 28, 1957 2 Sheets-Sheet 1 wam June 21, 193.8. 1.. J. WHITE 2,121,674

LIQUEFIED GAS STORAGE AND DISBENSING SYSTEM Filed May 28, 1937 2 Sheets-Sheet 2 Patented June 2i, 1938 Texas Loyd J. White, San Antonio,

Southern Steel Company,

Tex., assignor to a corporation of Application May 2%, 1937, Serial No. 145,352

26 Claim.

This invention relates to liquefied gas storage and dispensing systems of the general type disclosed in my Patent No. 2,042,439. The main idea is to provide a greatly simplified system for dispensing gas which is generated from highly volatile hydrocarbon liquid fuels, such as butane, propane, isobutane and/or mixtures of the same and having novel means for returning condensate formed in the service conduit or pipe to the storage tank, thus dispensing with the necessity of employing any heat exchanger to revaporize such condensate.

Other aims and advantages of theinvention will appear in the specification, when considered in connection with the accompanying drawings; wherein:

Fig. 1 is a vertical sectional view, partly in elevation, showing an underground storage and dispensing system embodying the invention;

Fig. 2 is a vertical sectional view of a combined pressure regulator and condensate returnvalve shown in Fig.1;

Fig. 31s a sectional view taken on the line 3-3 of Fig. 2; and

Fig. 4 is a sectional view taken on the line t-fl of Fig. 2.

Referring particularly to the drawings, there is shown a storage and dispensing system of the type adapted to be used for either domestic or commercial purposes wherein a storage tank ill, which is adapted to be partially filled with liquefled gas, is usually buried in the ground below the frost line in heat exchanging relation with the surrounding earth fill, so that the heat of the earth will vaporize the liquefied gas and deliver it at a substantially constant pressure. However, the invention is also applicable to systems in which the tank is above the ground. In this inv stance, the tank is adapted to be filled through 40 an ordinary filler pipe ll having a well known type of filler check valve it at the top and a back flow check valve l3 on the inside of the tank-at the bottom. The check valve it will prevent any gas from escaping from the tank in case the pipe breaks or the filler valve does not function properly. There is alsoshown a vapor outlet pipe or conduit Hi connected to the tank having an automatic vapor check valve l5 at the top adapted to be connected to a vent hose leading to the vapor space of an ordinary service truck tank (not shown). An ordinary excess flow check valve it is preferably connected to the bottom of the vapor outlet pipe and extends downwardly into the tank to the desired liquid level in the tank.

This check valve. also prevents the escape of any vapor in case the conduit l5 breaks or the vapor valve l5 fails to function. It will be understood that the filling hose of a service truck tank is adapted to be connected to the filler valve l2 and the displaced gas will flow from the tank through the vapor outlet to the service truck tank until the liquid rises to the level of the bottom of the check valve It which serves as a dip pipe. In this instance, a standpipe or conduit H is connected to the tank and carries the usual liquid level gauge it operated by a float l9 and this pipe has a fitting at the upper end carrying a pressure gauge 20 and a safety relief valve 2|.

The apparatus, thus far described, forms no part of this invention. It is illustrated to show an operative system. In accordance with the present invention, the gas generated in the tank is delivered through a fitting 22 secured to the tank and carrying a conventional manually operated cut-oil valve (not shown) within a valve casing 23. After passing through the valve, it is delivered through a conduit 2% in a screw threaded fitting 25 secured by a coupling nut 26 to a lower extension 21 of a regulator casing 28 which carries a diaphragm 29. The upper end of the conduit 2% terminates in a nozzle having a valve seat 39 which cooperates with a plunger valve M in the extension 21. This valve is connected to be operated by the diaphragm 29 to maintain the desired low pressure. In this instance, the diaphragm carries a bifurcated stud or bracket 32 pivotally connected to the upper end of a bell-crank-lever 33 which, in turn, is pivoted at its lower end portion on a pin 34. The other arm of the lever has an elongated slot 35 engaging a. pin 36 extending through the upper bifurcated end of the valve plunger 3i. An adjustable. compression spring 31 carried by the usual bonnet 38 of the regulator acts upon the opposite side of the diaphragm from the lever.

I It is adjusted by an ordinary set screw 39 to vary its compression. It will be understood that the spring serves to hold the valve 3l open until a predetermined low pressure is reached in the regulator casing, when the pressure acts in the opposite direction on the diaphragm to close the valve 36. The low pressure gas is delivered through the usualservice pipe Mi which is connected to one side of the extension Zlof the regulator casing adjacent to the vapor valve seat 30. Incidentally, the point of connection of the service pipe Ml to the extension is the lowest point in the service main or pipe so that any condensate formed therein will drain back into the extension, which provides a catch basin.

The regulator housing 29 is shown as having the usual safety relief valve 4|. Also, the high pressure gas dispensing conduit 24 in the fitting 25 is shown as being provided with an ordinary excess flow check valve comprising a fitting 42 screwed into the lower end of the conduit and carrying a small ball check 43 which is adapted to close due to an excessive rate of flow of gas.

The casing 28 ofthe pressure relief valve is shown as carrying a removable strap metal bracket 44 welded or otherwise secured to the standpipe l1 and a vent pipe 45 connected to the safety relief valve 4! extends upwardly above the casing and is reversely bent near the top of the standpipe where it is secured thereto by a suitable clamp 46. All of the dispensing and filling appliances are shown as being arranged in a protecting casing 41 having the usual cover 48, and the arrangement is such that the parts are not flooded by surface water.

In accordance with the present invention, the regulator valve mechanism is also employed to operate a condensate return valve so that any condensate formed in the service pipe will be returned to the tank It while the gas regulator valve is closed. Herein, the fitting 25 has a' separate condensate return conduit 49 terminating at its upper end in a valve seat 50 which is controlled by a plunger valve similar to the valve 3|, and has a pin 52 in its bifurcated upper end arranged in the slot 35 of the lever 33 so that both valves are operated by the same lever. The

'two plungers are shown as being arranged side by side within the extension 21 and are guided in their movement by the inside wall of the extension. They are held in their proper relation to their respective valve seats by the lever and the bifurcations at their upper ends and the litting 25 is alined with them by means of a. suitable guide pin 53 extending through one side of the extension 21. Incidentally, the valve seat 50 is below the vapor valve seat 30 and its valve is adapted to open about twice as much as the vapor valve 3! to permit condensate which is trapped in that portion of the extension 21 below the service line 4|! to flow freely into the return conduit 49 when the valve is open. The bottom of the conduit 49 is normally closed by a ball check valve 54 in a screw threaded fitting 55 when the valves 3i and El are open. This valve is very sensitive, having a much larger ball than the excess flow check valve in the other conduit so that it will close instantly when the valve 5! is gpened. However, its seat is scratched or unground so as to permit slight leakage of gas through it. A leaking groove 56 is shown merely for the purpose of illustration. An ordinary screw plug 57 is connected to the extension 21 adjacent to the two valves to afford easy access to them for renewing the valve washers without dismantling or disconnecting the regulator,

Referring to the operation of the valves, it will be understood that both the gas dispensing valve 30 and the condensate return valve 50 open simultaneously due to a reduction in pressure in the service main and in the diaphragm casing 28. As soon as the valves are opened, the ball check valve 54 closes while the excess flow check valve 43 will remain open under normal conditions. Any condensate formed in the service pipe 40 will drain into the extension 21 and through the open valve into the conduit 49, where it is temporarily trapped, while the dispensed gas flows through the other valve well above the condensate level. As soon as both valves close,

the condensate which has drained into the conduit 49 will be temporarily trapped and the-pressure within the conduit will be equalized with the pressure in the tank by the leakage of gas through the seat of the valve 54. Then, the valve 54 will drop and open, permitting the trapped condensate to flow by gravity into the tank. This is repeated automatically as the valves open and close, and prevents any condensate from clogging up the system, evenin very cold climates. The size of the condensate conduit or trap and the catch basin for it may be varied, depending upon -the size of installation to be made.

Fromthe foregoing description, it will be seen that the novel system is very simple in construction and automatic in operation; The provision of the automatic condensate return to the storage tank in conjunction with the pressure regulating valve eliminates the necessity of providing any external source of heat to revaporize the condensate formed in the service main.

Obviously, the present invention is not restricted to the particular embodiment thereof herein shown and described. Moreover, it is not indispensable that all the features of the invention be used conjointly, since they may be employed advantageously in various, combinations and sub-combinations.

What is claimed is:

1. In a liquefied gas storage and dispensing system of the class described, a pressure storage tank; a service pipe; means to deliver gas from the tank to the service pipe at a reduced pres:

sure; and intermittently operated means com-' municating with the lowest portion of the service pipe connected to return condensate formed therein to the tank.

2. In a liquefied gas storage and dispensing system of the class described, a; storage tank; a service pipe; means to deliver gas from the tank to the service pipe at a reduced pressure; and an intermittently operatedvalved trap connected to the lowest point of the service pipe automatically to trap and return condensate formed therein incident to fluctuations in the pressure of the gas in the service pipe.

3. In a. liquefied gas storage and dispensing system of the class described, a storage tank; a dispensing conduit connected to the tank; an intermittently operable, pressure reducing regula tor connected to the conduit; a service pipe communicating at its lowest point with the regulator; and valved trap means associated with the regulator and connected to be operated thereby to trap and return condensate formed in the service pipe to the tank.

4. In a liquefied gas storage and dispensing system of the class described, a storage tank; a dispensing conduit connected to the tank; a pressure reducing regulator connected to the conduit; a service pipe communicating at its lowest point with the regulator; a condensate return conduit communicating with thetank and arranged to receive condensate from the service pipe; a valve for said condensate conduit connected to be operated by said regulator; and a leaky check valve in the lower endiof said condensate conduit whereby a small quantity of high pressure gas in the tank will escape into and equalize the pressure in the condensate conduit with that in the tank when the condensate is trapped in the conduit by the regulator operated valve to permit thecondensate to flow; by gravity into the tank.

5. In a liquefied gas storage and dispensing 76 system of the class described, a storage tank; a dispensing conduit connected to the tank; a pressure reducing regulator connected to the conduit; a service pipe communicating at its lowest point with the regulator; a condensate trap communicating with the tank and having a valve operated by said regulator; and means to equalize the pressure in the trap with the pressure in the tank and permit trapped condensate to flow into the tank.

6. In a liquefied gas storage and dispensing system of the class described, a storage tank; a

dispensing conduit connected to the tank; a pressure reducing regulator connected to the conduit; a service pipe communicating at its lowest point with the regulator; a condensate trap communicating with the tank and having a valve operated by said regulator; and a leaky check valve in the lower portion of the trap normally closed by the pressure in the tank but adapted to open when the pressure in the trap is equalized with the pressure in the tank to permit the trapped condensate to 'fiow into the tank.

'7. In a liquefied gas storage and dispensing system of the class described, a storage tank; a dispensing conduit connected to the tank; a pressure reducing regulator connected to the conduit; a service pipe communicating at its lowest point with the regulator; a condensate trap communicating with the tank and having a valve operated by said regulator; a condensate return conduit arranged to receive condensate formed in the service pipe; a valve at the upper end of said condensate conduit connected to be operated by said regulator so that returned condensate may fiow into the conduit when *aeioi valve is opened; and a leaky check valve in the lower end portion or thecondensate conduit normally closed by the pressure in the tank but adapted to open when the pressure in. the conduit is squat ized with the pressure in the tank to permit the trapped condensate to fiow into the tank.

8. In a liquefied gas storage and dispensing system of the class described, a storage tank; a dispensing 'conduitconnected to the tank; a pressure reducing regulator connected to the conduit; 2. service pipe communicating at its lowest point with the regulator; a condensate trap communicating with the tank and having a valve operated by said regulator; a condensate return conduit arranged to receive condensate feed in the service pipe; a valve at the upper end of said condensate conduit connected to be operated by said regulator so that returned condensate may fiow into the conduit when said valve is opened; and automatic means establishing communication between the conduit and the tank when the condensate is trapped in the conduit.

9. In a liquefied gas storage and dispensing system of the class described, a storage tank; a regulator'casing having a tubular lower extension on its low pressure side; .a fitting having a gas dispensing conduit and a condensate return con duit connected to said extension and communicating with the tank; adjacent valves for the upper ends of the conduits; means in the regulator casing connected to operate both valves simultaneously; a service pipe connected at its lowest level to said tubular extension above the upper endlof the condensate conduit; and a leaky check valve in the lower end of the condensate returnv conduit operable to open and permit trapped condensate in said conduit to flow into v the tank.

end with said tank, the gas system of the class described, a storage tank; a regulator casing having a tubular lower extension on its low pressure side; a spring urged diaphragm in the regulator casing; a fitting having a gas dispensing conduit and a condensate return conduit connected at its upper end to said tubular extension and communicating at its lower dispensing conduit extending above the level of the condensate conduit; adjacent plunger valves for said conduits guided in said tubular extension; a lever connected to said diaphragm to operate both of said valves; a gas service pipe connected at its lowest level to said tubular extension adjacent to said valves .to drain condensate formed therein into the tubular extension above the upper end of the condensate conduit; and a ball check valve in the lower end of the condensate conduit adapted to be closed by the pressure in the tank so that condensate may be trapped in the conduit when the plunger valve opens and closes but having a slight leak to permit gas from the tank to escape into and equalize the pressure in the conduit with that in the tank whereby the trapped condensate will flow into the tank while the diaphragm operated valves are closed.

11. A combined pressure reducing regulator and condensate return trap comprising, in combination, a regulator casing having a depending tubular extension; a fitting removably secured in the lower end of said extension; a low pressure vapor outlet in the extension above the upper nd of said fitting providing a catch basin in the tubufit? lar extension; 9. high pressure vapor inlet conduit in the fitting having its upper end projecting above the bottom of the catch basin; a condensate. trapping conduit also in the fitting; adjacent plunger valves for both of said conduits having stems guided in said tubular extension; a diaphragm in the casing; a slotted bell-crank operable by the diaphragm; bifurcations and pins in the upper ends of said plunger valves connected to the slotted bell-crank; and a sensitive, leaky check valve in the lower end of said condensate trapping conduit to permit high pressure vapor to'leak slowly into the conduit and equalize the pressure of the condensate with that of the source of vapor when all of the valves are closed, whereby the check valve will open and the condensate will flow back to the source.

12. A combined pressure reducing regulator and condensate return trap comprising, in combination, a regulator casing having a depending tubular extension; a fitting removably 'secured in the lower end of said extension; a low pressure vapor outlet in the extension above the upper end of said fitting providing a catch basin in the tubular extension; a high pressure vapor inlet conduit in the fitting having its upper end projecting above the bottom of the'catch basin; a condensate trapping conduit also in the fitting; adjacent plunger valves for both of said conduits having stems guided in said tubular extension; a diaphragm in the casing; a slotted bell-crank operable by the diaphragm; bifurcations and pins in the upper ends of said plunger valves connected to the slotted bell-crank; means to hold the fitting with the valve seats of said con duits properly positioned with respect to the valves; an excess fiow check valve in the lower end of said vapor conduit;.and a sensitive, leaky check valve in the lower end of said condensate trapping conduit to permit high pressure vapor to leak slowly into the conduit and equalize the pressure of the condensate with that of the source iiit of vapor when all of the valves are closed, whereby the check valve will open and the condensate will flow back to the source.

13. A combined pressure reducing regulator and condensate return trap comprising, in combination, a regulator casing having a depending tubular extension; a valve fitting secured to the lower end of said extension; a low pressure vapor outlet opening in the extension; a vapor conduit and a condensate trapping conduit in the fitting having valve seats for said conduits; means in the regulator to operate both valves in response to variations in pressure of the delivered vapor; a leaky check valve in said trapping conduit permitting a small quantity of vapor to flow therethrough. and thereby equalize the pressure of the trapped conduits with that of the vapor source when all of the valves are closed so that the trapped condensate will flow back to the source of vapor; and a plugged opening in said tubular extension to afiord access to said valves.

14. In combination with a pressure reducing regulator of the class described, a condensate trap communicating with the low pressure side of the pressure regulator to catch condensed vapor drained thereto; and means on the trap connected to. be operated and controlled by the ac .tion of said regulator to trap andreturn condensate to the vapor source.

15. In combination with a vapor pressure reducing regulator of the class described, a condensate trap arranged to catch condensed vapor formed on the low pressure side of the regulator; a valve for the trap connected to be operated by said regulator; and means associated with the trap automatically operable when the valve is closed to permit trapped condensate to fiow back to the vapor source. I

16. In combination with a vapor pressure reducing regulator of the class described, a valved condensate trap associated with the regulator and arranged to .catch condensed vapor formed on the low pressure side of the regulator; and means connecting the regulator to open and close the trap whereby trapped condensate may be returned to the vapor source. I

17. In combination with'a vapor pressure reducing regulator, a casing having a high pressure vapor inlet and a low pressure vapor outlet; a valve on the inlet operable to reduce pressure be-- tween the inlet and outlet; 9. condensate trap communicating with the outlet and the source of high pressure; and intermittently operable means associated with the trap to transfer condensate. formed on the low pressure side of the regulator to the source of high pressure.

18. In combination with a vapor pressure reducing regulator of the class described, a condensate trap associated with .the regulator and arranged to catch condensed vapor formed on the low pressure side of the regulator; and valve means connected to be operated intermittently to trap condensate and return it to the vapor source.

19. In combination with a vapor pressure reducing regulator, a high pressure vapor inlet conduit; a diaphragm controlled pressure reducing valve for said inlet conduit; a condensate trap arranged to catch condensed vapor formed on the low pressure side of a regulator; an inlet valve for opening and closing said trap also connected to be operated by said diaphragm; and means in the trap operable to equalize the pressure on the trapped condensate with that of the vapor supply and thereby permit the trapped condensate to return to the vapor source.

20. In combination with a vapor pressure reducing regulator, a high pressure vapor inlet conduit; a diaphragm controlled pressure reducing valve for said conduit; a condensate return conduit connee'ed to receive condensed vapor formed on the luW pressure side of the regulator; a valve for said condensate return conduit also connected to be operated by the regulator; and means in the condensate conduit permitting the trapped condensate to return to the vapor source after the valve' for said condensate conduit is closed by said regulator.

21. In combination with a vapor pressure reducing regulator; a casing having a high pressure vapor inlet and a low pressure vapor outlet; a valve on the inlet operable to reduce pressure between the inlet and outlet; a condensate trap communicating with the outlet 'and the source of high pressure; a valve on the low pressure side of said trap connected to be intermittently operated to open and close the trap; and an automatic valve on the high pressure side of the trap operable to equalize the pressure in the trap with that of the vapor source when said intermittently operable valve is closed whereby trapped condensate may flow back to the vapor source.

22. In combination with a vapor pressure reducing regulator, a, casing having a high pressure vapor inlet conduit and a diaphragm controlled, pressure reducing valve therefor; a separate condensate return conduit connected to the low pressure side of the regulator casing; a valve for said condensate return conduit arranged adjacent to said pressure reducing valve; means connecting said valve for the condensate conduit to be operated by the regulator simultaneously with the regulator valve; and means in the trap operable to equalize the pressure on the trapped condensate with that of the vapor supply and thereby permit the trapped condensate to return to the vapor source.

23. A combined pressure reducing regulator and condensate return trap comprisingin combination, a regulator casing having a depending tubular extension; a valve fitting secured to the lower end of said extension; a low pressure vapor outlet in the extension; a high pressure vapor inlet conduit in the fitting having a valve seat in the lowerportion of said extension; a valve for said conduit; a condensate trapping conduit in the' fitting also having a valve seat in the lower portion of said extension; a valve for said trapping conduit; means in the regulator to operate both valves in response to variations in pressure of the delivered vapor; and means in the condensate conduit permitting the trapped condensate to return to the vapor source.

24. A combined pressure reducing regulator and condensate return trap comprising, in combination, a regulator casing having a depending tubular extension; a valve fitting secured to the lower end of said extension; a. low pressure vapor outlet in the extension; a high pressure vapor inlet conduit in the fitting having a valve seat in the lower portion of said extension; a, valve for said conduit; a condensate trapping conduit in the fitting also having a valve seat in the lower portion of said extension; a valve for said trapping conduit; means in the regulator to operate both valves in response to variations in pressure of the delivered vapor; and a leaky check valve in said trapping conduit permitting a small quantity of vapor to flow therethrough and thereby arena-re and condensate return trap comprising, in combination, a regulator casing having a depending tubular extension; a valve fitting secured to the lower end of said extension; a low pressure vapor outlet in the extension; at high pressure vapor inlet conduit in the fitting; a valve for said conduit; a diaphragm in the regulator casing; a lever operable by said diaphragm and connected to actuate said valve; a condensate trapping conduit;

a valve therefor connected to be operated simultaneously with the inlet conduit valve; and means in the condensate conduit permitting the trapped condensate to return to the vapor source. 26, A combined pressure reducing regulator a and condensate return trap comprising, in combination, a regulator casing having a depending tubular extension; a valve fitting secured to the lower end of said extension; a low pressure vapor outlet in the extension: a, high pressure vapor inlet conduit in the fitting having a valve seat in the lower portion of said extension; a valve for said conduit; a condensate trapping conduit in the fitting also having a valve seat in the lower portion 01' said extension; a valve for said trapping conduit; a diaphragm in the regulator casing; a slotted, bell-crank lever pivoted in the easing and operable by said diaphragm; stems on said valves guided to reciprocate in said tubular extension and connected to be actuated by said lever; and means in the condensate conduit permitting the trapped condensate to return to the vapor source.

. LOYD J. WHITE. 

